How to change $ to HK$?

Based on the documentation: https://easydigitaldownloads.com/docs/adding-currency-support-edd_currencies/, I have now added the following code to functions.php:

add_filter( 'edd_hkd_currency_filter_before', function( $formatted, $currency, $price ) { return 'HK$ ' . $price; }, 10, 3 );

This operation has already met my requirements, and I hope no other issues will arise. Thank you.